Trap door to prevent water from descending into starter bar pit

ABSTRACT

An apparatus for deflecting the flow of water into the casting path of a continuous-casting machine. A trap door is hingedly fixed above a starter bar exit hole in a casting guide mechanism. The trap door is pivoted out of the path of the starter bar to permit the bar access to the bar receiver and is pivoted into position over the access hole to deflect cooling water down the casting guide. The trap door may be made of a marginal frame covered by a thin sheet of readily penetrable material.

United States Patent Hofmann et al.

[54] TRAP DOOR To PREVENT WATER FROM DESCENDING INTO STARTER BAR PIT[72] Inventors: Gottfried Holmann, Brentwood, Allegheny County; James T.Stull, Jackson Township, Butler County, both of Pa.

[73] Assignee: United States Steel Corporation [22] Filed: Sept. 10,1970 [2]] Appl. No.: 70,973

[521 [1.5. CI. ..l64/274, 164/282 [51] Int. Cl ..B22d 11/08 [58] Fieldof Search 164/82, 274, 282, 283

[56] References Cited UNITED STATES PATENTS 3,338,297 8/1967 Foldessy164/274 [1;] 3,670,804 [451 June 20, 1972 3,520,351 7/1970 Rankin..l64/82 X FOREIGN PATENTS OR APPLICATIONS 982,981 2/ 1965 Great Britain..164/282 Primary Examiner-R. Spencer Annear Attorney-Ralph H. DoughertyABSTRACT marginal frame covered by a thin sheet of readily penetrablematerial.

5 Claim, 3 Drawing Figures TRAP DOOR TO PREVENT WATER FROM DESCENDINGINTO STARTER BAR PIT This invention relates to the continuous casting ofmetals and more particularly, to a novel means for preventing water fromdescending into a starter bar receiver.

It is customary in the continuous casting of metals to provide anapparatus comprising a vertical tubular mold open at the upper end forreceiving molten metal and open at the lower end for the discharge of ametal casting, water sprays located below the mold for directing coolingwater against the casting as it descends, guide rolls between the bottomof the mold and the bending means, bending means comprising a pluralityof bending rolls for bending the continuously-formed casting into acurved path, a curved-casting guide containing additional guide rollslocated beneath the bending rolls, and straightening rolls located atthe point at which the curved casting is tangent to the horizontal.

When molten metal is initially poured into the mold, the lower end ofthe mold is closed by the insertion of a starter bar into the bottom ofthe mold. If the starter bar is of the rigid type, provision must bemade for disconnecting the starter bar from the, casting and moving itfrom the path of the casting as, or before, the casting commences tobend. One such apparatus is shown in Foldessy US; Pat. No. 3,447,591. Insuch apparatus a portion of the casting guide is removed to allow thestarter bar to pass. Where the bending rolls are spaced from theadditional guide rolls in the casting guide, an entry chute is utilized,which chute has a hole to admit passage of a starter bar. The lower endof the starter bar, after passing through such hole, is brought straightdownwardly by a suitable means, such as a traveling receptacle. When thetension between the starter bar and the casting is relieved as theleadingedge of the starter bar contacts the receptacle, disconnection ofthe bar from the casting commences. Starter bar disconnect mechanismsare well known in the art and therefore are neither shown in thedrawings nor described herein. After the starter bar parts from thecasting, its rate of descent is increased and the bending rolls areactuated to initiate bending of the casting. While the casting is movingthrough the guide'roll rack, it is desirable to deliver a great flow ofcooling water on the casting to maintain a high rate of solidificationof the castings liquid core. l-leretofore large quantities of coolingwater have accompanied the starter bar into the receiver wherein it isstored.

It is the primary object of the present invention to provide means fordiverting as much cooling water as possible from the starter barreceiver to the chute and the curved-casting guide.

It is also an object of the invention to provide means for preventingdamage to the continuous-casting equipment when the starter bar path isinadvertently blocked.

7 We have found that by placing a trap door on the inside ofthe chute,we can provide access to the receiver for the starter bar when desired,yet once the starter bar has completely passed through the opening, thedoor may be closed and all succeeding cooling water will thereupon bediverted to the path of the casting.

In the drawings:

FIG. 1 is a side elevational view of a portion of a continuous-castingmachine.

FIG. 2 is a sectional view taken through the chute along line lI--ll ofFIG. .1.

FIG. 3 is a plan view of the trap door.

In the continuous-casting process depicted inFlG. 1, a

only in outline. Chute 20 has an opening 25 therethrough directly in thevertical path of the starter bar. Immediately beneath opening 25 is astarter bar passageway 26 having a traveling receptacle (not shown)therein and terminating in a bar storage pit (not shown).

Referring now to FIG. 2, opening 25 is shown covered by a trap door 30.The door 30 comprises a rectangularly-shaped marginal metal frame 31,the opening in the center of which corresponds approximately to the sizeof opening 25 in chute 20. A thin sheet of easily penetrable material33, such as aluminum, light gage steel sheet or even wood, is held inposition by retaining ring 34 and cap screws 35. Alternatively, door 30may be a single thin steel plate. The door has a pair of hinges 37 fixedto frame 31 by some means, such as welding. A hinge support 39 is fixedto the side of chute 20. A hinge pin 40, which is rotatable in support39 is fixed to hinges 37 by keys 41. A hinge pin lever am 43 is fixedt-o hinge pin 40 by means of drift pin 44. A hydraulic lever armactuating cylinder 46 is pivotally attached atits upper end to a pin 48joumaled in stationary housing 49 which is fixed to the chute 20. Thepiston rod 50 of cylinder 46 terminates in rod eye 51 which is pivotallyattached to lever arm 43 by pin 52. g

In operation, the door 30 is normally closed at the beginning of acasting operation. As the leading edge of the starter bar approacheschute 20, door 30 is moved to the open position shown in dotted outlinein FIG. 2. Cylinder 46 is actuated to extend piston rod 50, which forceslever arm 43 to rotate clockwise about the axis of hinge pin 40. Pin 44causes pin 40 to rotate with arm 43,and keys 41 cause hinges 37 likewiseto move the pin. 40 opening trap door 30. Starter bar 10 passes throughhole 25 in chute 20. As the leading end of the bar contacts a travelingreceptacle, whereby it is lowered into the receiver, tension in theconnection between the casting and starter bar is relieved. At this timethe bending roll 14 is actuated to deflect the casting, disconnecting itfrom the starter bar. When parting is completed, the rate of descent ofthe starter bar greatly increases. Considerable distance developsbetween the leading end of the casting and the top of the starter bar.When the starter bar has completely passed through the hole 25, cylinder46 is actuated to retract piston 50, which forces lever arm 43 to rotateabout the axis 'of hinge pin 40. Pin 44 causes pin-40 to rotate with arm43, and keys 41 cause hinges 37 to likewise move the'pin 40 closing trapdoor 30. Cooling water will no longer exit through hole 25 into thestarter bar receiver but will now continue to flow down the starter bar10 is positioned in the bottom of a continuous casting mold (not shown)and extends downwardly toward bending roll assembly 12. Casting isinitiated, and starter .bar 10 moves downwardly through the bending rollassembly. A bending roll 14 extends downwardly from the assembly and isattached thereto by pivoted arms 16. Water sprays 17, between the moldand the bending roll assembly, direct cooling water on the starter barand casting. A chute 20 is located in the vertical path of the castingand is so positioned to assist the entry of casting 22 intocurved-casting guide 23, shown a guide.

The trap door that includes an aluminum sheet 33 is preferred. If thedoor is not open when the leading end of the starterbar reaches it, thebar will rupture the aluminum sheet causing no further damage to theequipment and will pass through hole 25 into the starter bar receiverwithout causing a shutdown of the casting operation. The aluminum sheetis easily replaceable for the next cast.

' It can readily be seen from the foregoing that we have invented ameans for diverting maximum quantity of cooling bending means, areceiver for holding said starter bar, and.

means above said bending means for spraying water on said casting, theimprovement comprising a trap door of readily penetrable materialbetween said bending means and said receiver which trap door opens toallow said starter bar to pass into said receiver and closes to preventwater from entering said receiver and which trap door may be penetratedby the starter bar causing no further damage to the equipment should thetrap door be closed when the starter bar reaches it.

2. Apparatus as described in claim 1 in which said trap door 4.Apparatus as described in claim 2 in which said penetracomprises amarginal metal frame having a sheet of said readil al E Wood- ]ypenetrable material rcmovably affixed theret 5. Apparatus as describedin claim 2 in which said penetra- 3. Apparatus as described in claim 2in which said penetrable material is steel ble material is aluminum. 5 w-oid

1. In a continuous-casing machine including means for bending a castingfrom a vertical path to a horizontal path, a vertically movable starterbar which is disconnected from the leading end of the casting as saidleading end reaches said bending means, a receiver for holding saidstarter bar, and means above said bending means for spraying water onsaid casting, the improvement comprising a trap door of readilypenetrable material between said bending means and said receiver whichtrap door opens to allow said starter bar to pass into said receiver andcloses to prevent water from entering said receiver and which trap doormay be penetrated by the starter bar causing no further damage to theequipment should the trap door be closed when the starter bar reachesit.
 2. Apparatus as described in claim 1 in which said trap doorcomprises a marginal metal frame having a sheet of said readilypenetrable material removably affixed thereto.
 3. Apparatus as describedin claim 2 in which said penetrable material is aluminum.
 4. Apparatusas described in claim 2 in which said penetrable material is wood. 5.Apparatus as described in claim 2 in which said penetrable material issteel.